Equipment
* optional
Ingredients
Pickled Rhubarb
- 150 g rhubarb, cut into 1cm cubes
- 100 ml white wine vinegar
- 100 g caster sugar
- 100 ml water
Sweet and Sour Mackerel
- 400 g mackerel fillets, skin-on, pin-boned
- 15 g sea salt
- 150 ml white wine vinegar
- 50 g caster sugar
- 50 ml water
Almond Gazpacho (Ajo Blanco)
- 150 g blanched almonds
- 50 g white bread, stale, crusts removed
- 300 ml water, ice cold
- 1 garlic, peeled
- 50 ml extra virgin olive oil
- 15 ml sherry vinegar
- 5 g sea salt
Garnish
- 5 g fresh dill, picked into small fronds
- 10 ml extra virgin olive oil
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 758 kcal
- Protein
- 28 g
- Carbohydrates
- 55 g
- Fat
- 48 g
- Fiber
- 6 g
- Sugar
- 40 g
- Sodium
- 2105 mg
- Saturated Fat
- 7 g
- Trans Fat
- 0 g
- Monounsaturated Fat
- 28 g
- Polyunsaturated Fat
- 10 g
- Cholesterol
- 70 mg
- Potassium
- 731 mg
- Calcium
- 173 mg
- Iron
- 3.8 mg
- Magnesium
- 188 mg
- Phosphorus
- 421 mg
- Zinc
- 2.0 mg
- Vitamin A
- 57 mcg
- Vitamin C
- 5 mg
- Vitamin D
- 16.1 mcg
- Vitamin E
- 13.4 mg
- Vitamin K
- 25 mcg
- Vitamin B6
- 0.5 mg
- Vitamin B12
- 8.7 mcg
- Thiamin
- 0.32 mg
- Riboflavin
- 0.81 mg
- Niacin
- 11.1 mg
- Folate
- 35 mcg
- Water
- 281 g
Sources: Aggregated Public Data, USDA FoodData Central
Method
In a small saucepan, combine 100ml white wine vinegar, 100g caster sugar, and 100ml water for the pickled rhubarb. Bring to a boil at 100 C (212 F), stirring until sugar dissolves. Pour the hot liquid over the diced rhubarb in a mixing bowl and let it cool completely.
In the same small saucepan, prepare the mackerel pickling liquor by bringing 150ml white wine vinegar, 50g caster sugar, and 50ml water to a boil. Once dissolved, remove from heat and chill in the refrigerator until ice cold.
Place the mackerel fillets flesh-side up in a dish. Sprinkle evenly with the 15g of sea salt. Let sit at room temperature for 30 minutes to draw out excess moisture and firm the flesh.
Rinse the salt off the mackerel fillets under cold running water and gently pat them completely dry with paper towels. Submerge the fillets in the fully chilled sweet and sour pickling liquor for exactly 2 hours in the refrigerator.
While the mackerel cures, prepare the gazpacho. Tear the stale bread into chunks and soak it in 100ml of the cold water in a small bowl for 10 minutes to soften.
Transfer the soaked bread, blanched almonds, garlic clove, sherry vinegar, sea salt, and the remaining 200ml of cold water to a high-speed blender. Blend on high until completely smooth, about 2 minutes.
With the blender running on a medium-low speed, slowly stream in the 50ml of extra virgin olive oil until the mixture is fully emulsified. Transfer to a container and chill in the refrigerator until serving.
Remove the mackerel from the pickle and pat dry. Starting from the head end, use a sharp knife or fingernail to catch the edge of the transparent outer membrane on the skin, and carefully peel it off in one piece. Slice the mackerel into 1.5cm wide pieces.
Pour a pool of the chilled almond gazpacho into shallow bowls. Arrange 4 to 5 slices of cured mackerel in the center. Scatter drained pieces of pickled rhubarb around the fish. Garnish with fresh dill fronds and drops of extra virgin olive oil.
Chef's Notes
- Peeling the transparent outer skin of the mackerel after curing is crucial. It drastically improves the texture, resulting in a tender, melt-in-the-mouth bite rather than a chewy finish.
- If your blender struggles with almonds, use almond meal instead, but be aware it may require an extra pass through a fine sieve to achieve the signature silky texture of ajo blanco.
- Cross-contamination is a risk when working with fish that undergoes a cold-cure rather than heat cooking. Use a dedicated clean cutting board for slicing the final product, and thoroughly wash your fish tweezers.
- The rhubarb pickle liquor can be reserved and used in vinaigrettes or cocktails later in the week.
Storage
Refrigerator: 2 days — Store components separately. Mackerel quality degrades after 2 days.
Troubleshooting
Almond gazpacho is grainy or gritty
Cause: Blender not powerful enough or not blended for sufficient time
Fix: Pass the mixture through a fine mesh sieve (chinois) before emulsifying with oil
Prevention: Soak almonds in water overnight before blending, or blend for an extended period in a high-speed machine
Mackerel flesh is mushy or excessively opaque
Cause: Left in the acid cure for too long, or the pickling liquid was still warm when the fish was added
Fix: Cannot be fixed
Prevention: Strictly adhere to the 2-hour marinating time and ensure liquids are ice cold
Gazpacho splits or looks oily
Cause: Olive oil was added too quickly or blender was too hot
Fix: Blend a splash of ice water into the soup to re-emulsify
Prevention: Stream oil slowly while blending on a moderate speed. Ensure water used is ice cold.
Cultural Context
This dish draws heavily from Spanish Ajo Blanco, a traditional chilled soup originating from Andalusia that predates the introduction of tomatoes to Europe. By pairing it with mackerel prepared in an escabeche-style sweet and sour cure, the recipe bridges ancient Iberian preservation techniques with modern plating, utilizing the acidity of the rhubarb to slice through the rich oils of the fish and nuts.
